With the investment, Summit Partners has acquired a minority stake in the company, which markets its popular antivirus software based on a freemium model.

AVAST Software CEO Vince Steckler says the combination of offering a free product alongside a premium one has disrupted the tradition antivirus software market, where vendors often rely on advertising or installation fees for revenues. Steckler added that they’ll stick to this approach for the foreseeable future.

According to the company, its software suite – avast! antivirus – currently protects one out of every five computers around the world from malware. One of the co-founders of AVAST Software, Pavel Baudis, is cited as saying that the company’s Virus Lab adds around 3,000 new virus samples to its database on a daily basis, compared to a single virus emergence every six months when he wrote a program to remove the Vienna virus back in 1988.

We covered other Summit Partners investments in the past, including its participation in the $23 million round for Cloudmark together with Nokia Growth Partners.